Optimal Sequencing of Development for Hydropower Stations in Cascade

The sequencing problem for hydropower station development is a multidimensional problem involving space‐time decisions. In this paper, a mathematical model that uses a combination of dynamic programming and mixed‐integer programming is developed, and an efficient algorithm for its use in optimal sequencing problems is presented. The dynamic‐programming submodel (DPM) generates the alternative possible combinations of hydropower and thermal power stations (i.e., states) and analyzes the different sequences of hydropower station development. The mixed‐integer programming submodel (MIPM) simulates the operation of the power system and determines the minimum fuel‐cost operating policy. The MIPM requires an auxiliary flow regulation submodel (FRM). The combined use of the DPM, MIPM, and the FRM provides investment and operation decisions in one run. Therefore, the optimal development sequence of the hydropower stations and the timing of installation of power‐generating units in each station are obtained from the solution of the DPM‐MIPM‐FRM model. This model is applied to the preliminary planning of hydropower stations on the Wujiang River in the southwestern region of China, and the results are described.